Two-axis driving electromagnetic micro-actuator

Abstract

Provided is a two-axis driving electromagnetic actuator that includes a stage that is operative to be actuated about a first axis; an inner frame that that is disposed outside the stage and supports the stage by the first axis; an external frame that is disposed outside the inner frame and supports the inner frame by a second axis which is perpendicular to the first axis; a magnet that provides an electric field between the first axis and the second axis; a first driving coil that is formed on the inner frame and to which a first signal that actuates the stage in a direction of the second axis is applied; and a second driving coil that is formed on the inner frame and to which a second signal that actuates the stage and the inner frame in a direction of the first axis is applied, wherein the first driving coil and the second driving coil are electrically separated from each other.

1. A two-axis driving electromagnetic actuator comprising:
 a stage that is operative to be actuated about a first axis; 
 a middle frame that is disposed outside the stage and supports the stage by the first axis; 
 an inner frame that is disposed outside the middle frame and supports the middle frame by a second axis which is perpendicular to the first axis; 
 an external frame that is disposed outside the inner frame and supports the inner frame by the second axis; 
 a magnet that provides a magnetic field between the first axis and the second axis; 
 a first driving coil that is formed on the inner frame and to which a first signal that actuates the stage in a direction of the second axis is applied; and 
 a second driving coil that is formed on the inner frame and to which a second signal that actuates the stage and the inner frame in a direction of the first axis is applied, 
 wherein the first driving coil and the second driving coil are electrically separated from each other, 
 wherein the first driving coil and the second driving coil are disposed away from the stage. 
 
     
     
       2. The two-axis driving electromagnetic actuator of  claim 1 , wherein the first driving coil and the second driving coil are alternately formed. 
     
     
       3. The two-axis driving electromagnetic actuator of  claim 1 , wherein the first driving coil and the second driving coil are each wound on the inner frame an identical number of times. 
     
     
       4. The two-axis driving electromagnetic actuator of  claim 1 , wherein a high frequency signal is applied to the first driving coil and a low frequency signal is applied to the second driving coil. 
     
     
       5. The two-axis driving electromagnetic actuator of  claim 1 ,
 wherein the first signal comprises a high frequency current and the actuation of the stage by the first signal comprises rotation in a resonant mode, and 
 wherein the second signal comprises a low frequency signal and the actuation of the stage comprises rotation in a non-resonant mode. 
 
     
     
       6. The two-axis driving electromagnetic actuator of  claim 1 ,
 wherein the first axis comprises two oppositely disposed first torsion springs which connect the stage to the middle frame, and 
 wherein the second axis comprises two oppositely disposed second torsion springs, which connect the inner frame to the external frame, and two oppositely disposed third torsion springs which connect the middle frame to the inner frame. 
 
     
     
       7. The two-axis driving electromagnetic actuator of  claim 1 , further comprising:
 a third driving coil on the middle frame to which a third signal that actuates the stage in the direction of the second axis is applied; and 
 a fourth driving coil on the middle frame to which a fourth signal that actuates the stage in the direction of the first axis direction is applied, 
 wherein the third and fourth driving coils are electrically separated from each other. 
 
     
     
       8. The two-axis driving electromagnetic actuator of  claim 7 , wherein the third driving coil and the fourth driving coil are alternately formed. 
     
     
       9. The two-axis driving electromagnetic actuator of  claim 7 , wherein the third driving coil and the fourth driving coil are wound for a same number of times on the middle frame. 
     
     
       10. The two-axis driving electromagnetic actuator of  claim 7 , wherein a high frequency signal is applied to the third driving coil and a low frequency signal is applied to the fourth driving coil. 
     
     
       11. The two-axis driving electromagnetic actuator of  claim 7 , wherein the third driving coil is connected to the first driving coil, and the fourth driving coil is connected to the second driving coil. 
     
     
       12. The two-axis driving electromagnetic actuator of  claim 7 , wherein a natural frequency of the stage and the middle frame is equal to or less than 1/√{square root over (2)} of a driving frequency applied to the external frame. 
     
     
       13. The two-axis driving electromagnetic actuator of  claim 7 , further comprising a mirror surface on the stage that scans light.